The problem of smoking and the difficulty of cessation are well documented phenomena. Despite large numbers of successful quitters, approximately 54 million adults continue to smoke. Surprisingly, a majority of these individuals report that they would like to quit smoking. One approach that may hold promise for these smokers is to apply computer technology in a self-help format to individualize the treatment of smoking. The capacity of computers to individualize a cessation program based on research on nicotine addiction could provide an important break through in smoking cessation. Heretofore, individualization of self-help programs was virtually impossible. Likewise, even therapist led programs based on a nicotine addiction model have not individualized the treatment regimen. Behar, Inc. have developed a first generation, engineering prototype of a dedicated, hand-held computer that can provide smokers with a structured, self-help cessation program. The engineering prototype has been piloted with a number of smokers to determine its acceptability, smokers' compliance, and options for software design. The device, based on a systematic nicotine reduction model of treatment, defines reductions as a function of baseline smoking and adjusts for deviations from initially determined rates of reduction. Phase 1 funding will allow completion of a second generation field prototype computer; modification of previously developed support material; evaluation of a series of clinical trials; and assessment of the acceptability of the field prototype in focus groups for smokers. The accomplishment of these tasks would prepare us to conduct a large scale, well-controlled evaluation of the effectiveness of computer assisted cessation in a Phase 2 trial.